Search Results - The Complete Work of Charles Darwin Online

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

with a group which, owing to their small size and obscure colours, would attract little attention, but which nevertheless, by the universality of their presence, their curious habits, and the annoyance they often cause to man, are sure to force themselves upon the attention of every one who visits the tropics. Ants, Wasps, and Bees The hymenopterous insects of the tropics are, next to the butterflies, those which come most prominently before the traveller, as they love the sunshine, frequent

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

barometer at, 234 Bates, Mr., first adopted the word mimicry, 54 his observations on Leptalis and heliconid , 59 his paper explaining the theory of mimicry, 59 objections to his theory, 76 on recent immigration of Amazonian Indians, 100 on climate at the equator, 235 on scarcity of forest-flowers on Amazon, 264 on animal life in Amazon valley, 271 on abundance of butterflies at Ega, 274 on importance of study of butterflies, 277 on leaf-cutting ants, 282 on blind ants, 284 on bird-catching spider, 291

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

Belt, Mr., on leaf-cutting ants, 283 on an Acacia inhabited by ants, 285 on uses of ants to the trees they live on, 285 on a leaf-like locust, 288 on tree-frogs, 305 on the habits of humming-birds, 319 on uneatable bright-coloured frog, 351 on use of light of glow-worn, 374 Berthoud, on stone implements in tertiary deposits in America, 448 Betel-nut, 252 Bill of humming-birds, 315 Birds, possible rapid increase of, 23 numbers that die annually, 24 mimicry among, 73 dull colour of females, 80

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

cutting ant in America will thus explain why these specially modified plants are so much more abundant there than in the Old World, where no ants with equally destructive habits appear to exist. Wasps and Bees These insects are excessively numerous in the tropics, and, from their large size, their brilliant colours, and their great activity, they are sure to attract attention. Handsomest of all, perhaps, are the Scoliad , whose large and rather broad hairy bodies, often two inches long, are

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

, whose stomachs are often full of them; yet numbers of them escape destruction, and this can only be due to their vegetable disguises. Mr. Belt records a curious instance of the actual operation of this kind of defence in a leaf-like locust, which remained perfectly quiescent in the midst of a host of insectivorous ants, which ran over it without finding out that it was an insect and not a leaf! It might have flown away from them, but it would then instantly have fallen a prey to the numerous

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

plants, hitherto inexplicable, are due to the necessity of keeping away unbidden guests, such as snails, slugs, ants, and many other kinds of animals, which would destroy the flowers or the pollen before the seeds were produced. When this simple principle is once grasped, it is seen that almost all the peculiarities in the form, size, and clothing of plants are to be thus explained, as the spines or hairs of the stem and branches, or the glutinous secretion which effectually prevent ants from

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

Cassid , resemble dew-drops, 42 Caterpillars, mimicking a poisonous snake, 70 gaudy colours of, 82 various modes of protection of, 83 gooseberry caterpillar, 84 Mr. Jenner Weir's observations on, 84 Mr. A. G. Butler's observations on, 85 Cattleyas, 257 Cecropias, trees inhabited by ants, 285 Celebes, large and peculiarly formed butterflies of, 385 white-marked birds of, 388 Centipedes, 291 Centropus, sexual colouring and nidification of, 125 Cephalodonta spinipes, 66 Ceroxylus laceratus

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

fulicarius, 81, 132 Phasmid , imitate sticks and twigs, 46 females resembling leaves, 79 tropical forms of, 286 288 Pheasants, brilliant plumage of, in cold countries, 342 Pheidole, genus of ants, 281 Philippine islands, metallic colours of butterflies of, 385 Philippine islands, white-marked birds of, 388 Ph nix sylvestris, 251 Phyllium, wonderful protective colour and form of, 46 Phyllostoma, 308 Physalia, 136 Picari , 296 Picid , sexual colouring and nidification of, 125 Pierid and Lyc nid , local

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

fungi, 397 Smyth, Professor Piazzi, on the Great Pyramid, 430 Snakes, mimicry among, 72 characteristics of tropical, 304 Sobralias, 256 Soil, heat of, 222 influence of temperature on climate, 223 Solenopsis, genus of ants, 281 Song of birds, instinctive or imitative, 104 Sorby, Mr., on composition of chlorophyll, 395 Spalding, on instinctive actions of young birds, 109 Sparrow learning song of linnet and goldfinch, 105 Species, law of population of, 23 abundance or rarity of dependent on the

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

IV ON INSTINCT IN MAN AND ANIMALS THE most perfect and most striking examples of what is termed instinct those in which reason or observation appear to have the least influence, and which seem to imply the possession of faculties farthest removed from our own are to be found among insects. The marvelous constructive powers of bees and wasps, the social economy of ants, the careful provision for the safety of a progeny they are never to see manifested by many beetles and flies, and the curious

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

that of savages, 192 and plants under domestication, an example of Darwin's research, 459 Anisocerin , 66 Anoplotherium, 165 Anthribid , 290 mimicry of, 67 Anthrocera filipendul , 84 Anthropologists, wide difference of opinion among, as to origin of human races, 167 conflicting views of, harmonised, 179 Antiquity of man, 167, 180 in North America, 433 Ants, wasps, and bees, 278 numbers of, in India and Malaya, 278, 283 [page] 47

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

almost unchecked. It is perhaps in insects that we may best study the varied means by which animals are defended or concealed. One of the uses of the phosphorescence with which many insects are furnished is probably to frighten away their enemies; for Kirby any Spence state that a ground-beetle (Carabus) has been observed running round and round a luminous centipede as if afraid to attack it. An immense number of insects have stings, and some stingless ants of the genus Polyrachis are armed with

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

to the body, it seems probable that the insect would be more frequently struck or pierced in a vital part, and thus the increased expanse of the wings may have been indirectly beneficial. In other cases the capacity of increase in a species is so great that however many of the perfect insect may be destroyed, there is always ample means for the continuance of the race. Many of the flesh-flies, gnats, ants, palm-tree weevils, and locusts are in this category. The whole family of Cetoniad or rose

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

species of Hesthesis run about on timber, and cannot be distinguished from ants. There is one genus of South American Longicorns that appears to mimic the shielded bugs of the genus Scutellera. The Gymnocerus capucinus is one of these, and is very like Pachyotris fabricii, one of the Scutellerid . The beautiful Gymnocerus dulcissimus is also very like the same group of insects, though there is no known species that exactly corresponds to it; but this is not to be wondered at, as the tropical

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

ants' nests, the soft materials of which they can easily hollow out. Many terns and sandpipers lay their eggs on the bare sand of the sea-shore, and no doubt the Duke of Argyll is correct when he says that the cause of this habit is not that they are unable to form a nest, but that, in such situations, any nest would be conspicuous and lead to the discovery of the eggs. The choice of place is, however, evidently determined by the habits of the birds, who, in their daily search for food, are

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

12. Parrots (Psittaci). In this great tribe, adorned with the most brilliant and varied colours, the rule is that the sexes are precisely alike, and this is the case in the most gorgeous families, the lories, the cockatoos, and the macaws; but in some there is a sexual difference of colour to a slight extent. All build in holes, mostly in trees, but sometimes in the ground, or in while ants' nests. In the single case in which the nest is exposed, that of the Australian ground parrot, Pezoporus

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

found, and other tropical countries are no doubt equally rich. I will first give some account of the various species observed in the Malay islands, and afterwards describe some of the more interesting South American groups, which have been so carefully observed by Mr. Bates on the Amazons and by Mr. Belt in Nicaragua. Among the very commonest ants in all parts of the world are the species of the family Formicid , which do not sting, and are most of them quite harmless. Some make delicate

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

, usually with long antenn and legs, varied in form and structure in an endless variety of ways, and adorned with equally varied colours, spots and markings. Some are large and massive insects three or four inches long, while others are no bigger than our smaller ants. The majority have sober colours, but often delicately marbled, veined, or spotted; while others are red, or blue, or yellow, or adorned with the richest metallic tints. Their antenn are sometimes excessively long and graceful, often

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

certain modes of tropical life. Some live on ants upon the ground, others pick minute insects from the bark of trees; one group will devour bees and wasps, others prefer caterpillars; while a host of small birds seek for insects in the corollas of flowers. The air, the earth, and undergrowth, the tree-trunks, the flowers, and the fruits, all support their specially adapted tribes of birds. Each species fills a place in nature, and can only continue to exist so long as that place is open to it; and

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A238 Book: Wallace, A. R. 1895. Natural selection and tropical nature: Essays on descriptive and theoretical biology. London: Macmillan. Text Image

, owing to their numbers, their size, and their brilliant colours, as well as their peculiarities of form, and the slow and majestic flight of many of them. In other insects, the large size and frequency of protective colours and markings are prominent features, together with the inexhaustible profusion of the ants and other small insects. Among birds the parrots stand forth as the pre-eminent tropical group, as do the apes and monkeys among mammals, the two groups having striking analogies in the